Mexican American early adolescents in the 8th grade are at higher risk for use of a range of substances compared to Whites and African Americans (Johnston, O'Malley, Bachman, &Shulenberg, 2007). Since 1992 Hispanic/Latino Americans have reported the highest annual rates of illicit drug use among eighth grade students in national studies, as well as higher rates of recent alcohol use, intoxication, and binge drinking than students from other ethnic groups (Johnston et al., 2007). There are also important gender differences, with research showing that, although girls progress slower to drug use initiation than boys, once girls begin to use, they progress faster to rates of addiction than boys, when using the same amount of substances (Kauffman, Silver, &Poulin, 1997;NCASA, 2003). Gender roles are an understudied factor in understanding these ethnic group and gender differences in risk for substance use and abuse. The candidate has recently completed analyses (Kulis, Marsiglia, &Nagoshi, 2008), using a small data set of Mexican American adolescents, showing the significant relationships between positive and negative gender roles (assertive vs. aggressive masculinity, affective vs. submissive femininity) and substance use, including the significant mediating effects of internalizing/externalizing behaviors and peer substance use on the gender role-substance use relationship in girls. Given the traditions of machismo and marianismo in Mexican culture, gender roles may be a particularly important and understudied predictor of substance use in Mexican American adolescents, and the candidate's analyses built on studies of Mexican adults by Lara-Cantu, Medina-Mora, and Gutierrez (1990) and Mexican adolescents by Kulis, Marsiglia, Lingard, Nieri, &Nagoshi (2008). The proposed research will facilitate the candidate's career development by allowing her to test an expanded theoretical model, including positive and negative coping as additional mediators and acculturation as an additional moderator, of the relationships between positive and negative gender roles and substance use. This model will be tested through secondary analyses of a much larger data set of 955 (450 boys, 505 girls) Mexican American adolescents (7th to 8th grade), which will allow for the application of more sophisticated structural equation modeling techniques. Since gender roles are a product of childhood socialization, are linked to a wide range of psychological and social functioning, and are important for adolescent identity development, they are a particularly promising target for interventions to prevent substance use and misuse in adolescence.